I have a number of questions/issues:

1) we are using Person Accounts (yes our C&P app is set up for PA) and we store the billing information in the Account billing fields NOT the Contact Mailing fields but you seem only to take from Mailing fields. This is VERY bad for us as we use Mailing Address fields for something else which we do NOT want drawn into C&P and put on a receipt. What can we do about this?

2) Building on that, your UI for Transactions is not ideal for our needs (and VT isn't even in SF) and is not customizable. Therefore I created my own custom obj front end for users to enter in data and an embedded VT for the actual CC processing. However, I have the same problem as above, you don't seem to provide parameters to send billing info, only shipping.

3) So I am wondering, you have an inbound web service, correct? Would it just be possible for me to make a callout from SF to your web service and get a response, than trying to maneuver around your Transaction/VT model?

Thanks,
Dovid